1. Field of the Invention
This invention relates to inter-stage seal retainers used in gas turbine engine assemblies and, more particularly, to inter-stage seal retainers and assemblies to mount inter-stage turbine seals to nozzles or vane assemblies of gas turbine engines.
2. Discussion of the Background Art
Conventional turbine inter-stage seal retainers are often installed in assemblies that are configured such that they cannot be visually reviewed by the assembler after installation and after complete torquing of the attaching bolt and nut of the retainer. As a result, if too much relative rotation between the retainer and the item to be retained, such as a seal assembly in a turbine section of a gas turbine engine, is allowed, improper assembly is possible. Improper assembly includes having the retained part being clamped inadvertently in the bolted joint or for it to be damaged by the retainer upon application of clamp force due to the bolt during torquing.
The seal assembly in the turbine is intended to be able to translate relative to a nozzle stage of the turbine and the retainer is used to maintain its mounting to the nozzle while allowing limited axial movement.
In the past, proper retainer installation relied upon the experience and feel of the assembler. Radially extending tabs welded on nut cages of the retainer were also used to "fool proof" or insure proper orientation and installation of the retainer.